Primates
The primates are perhaps the most instinctively surviving mammals on the planet Earth. Human beings are primates and the list of primates goes way back in time when, Homo sapiens like us, include familiar animals like chimpanzees, gorillas, and monkeys, in addition to a few lesser known lemurs like lorises, and galagos. Two primates from different suborders could be the Prosimii or the prosimians, as they are commonly referred to, and the Anthropoidea, to which we as humans belong. Ring-tailed and ruffed lemurs, found in Madagascar are prosimians, while orangutans, apes, and humans belong to the anthropoidea group and are scattered across the face of Earth.
Lemurs, while dangling by their hind legs, pluck figs from the branch below. With their long and sharp nails, they are able to comfortably position themselves well to eat upside down. A lot of research has been going on to understand their eating behavior. According to Charnov (1976), and Stephens and Krebs (1986) in Stevens and Mühlhoff (2012), Behavioral Process: Intertemporal Choices in Lemurs, studies are being conducted to study the eating pattern of such lemurs. Questions like should a lemur continue to search for the remaining figs or move on to another branch full of fruit? These questions of when to leave a patch is an example of intertemporal choice; a choice between options with different time delays to reward, says Charnov, Stephens and Krebs. According to Stevens and Mühlhoff (2012), “Intertemporal choices is a continuous process in lives of humans and other animals, and when and where to forage, with whom to interact or mate, and where to establish a territory, individuals must choose between options whose benefits are available at different points in time. This goes to show that prosimians and lemurs in general, are very much like anthropoideas. “Experiments using pigeons and rats (McDiarmid and Rilling, 1965, and Richards et al., 1997) to study intertemporal choices were done frequently, but more recently, researchers have tested many more species, including insects, fish, birds, mice, and primates” (Bateson and Kacelnik, 1996, Tobin et al., 1996, Brunner and Hen, 1997, Cheng et al., 2002, Stevens et al., 2005a, Rosati et al., 2007, Pearson et al., 2010, Vick et al., 2010 and Mühlhoff et al., 2011). Madagascar is home to most kinds of lemurs. Lemurs are nocturnal, insectivorous primates who have small bodies, long nose, and large eyes. Because of their rarity, they are considered to be an endangered species. “As Madagascar continues to drift away from mainland Africa, and as monkeys appeared, these highly intelligent and adaptive primates drove the lemur lineage towards extinction. Only a few lemurs, like the bushbabies, lorises, and pottos, have managed to survive by retaining their nocturnal, solitary, and insectivorous traits” (wildlifemadagascar, n.d).
Researchers have investigated intertemporal choice and other forms of behavioral choices of prosimians through various methodologies, says Beran et al. (1999), and Stevens et al. (2005a). One particular method included the “adjusting-delay ‘self-control’ paradigm to test intertemporal choices in Old World monkeys, New World monkeys, and apes.” For the test, subjects make binary choices between two immediately available food items and six food items available after a time delay were observed. It is believed that prosimian species have never been tested in an intertemporal choice task. Lemurs, according to (Lewis et al., 2005 and Santos et al., 2005), are good species to test because there is already enough data available on their numerical discrimination, inhibitory control (Genty et al., 2004), and risk sensitivity (MacLean et al., in press).
According to King et al., (1988), the term primates include humans although for purpose of simplicity and distinction, he does not include them in his review of literature. King et al., (1988), says that “there are almost 200 primate species which include the great apes (chimpanzees, gorillas, and orangutans), lesser apes (gibbons and siamangs), Old World monkeys, New World monkeys, and prosimians.” Ninety-eight percent of human DNA can be found in the gene of chimpanzees, the most widely used of the great apes. Because of their similarities of genes and their biological mechanisms of humans and primates that these animals are subjected to research in a broad range of disciplines,” say King et al., (1988). It is because of this that monkeys and chimpanzees are mostly preferred for research “in the final tests analysis system for safety and efficacy of treatments, preventive agents and vaccines developed in studies with other laboratory animals,” say King et al., (1988).
Monkeys and chimpanzees can be seen all around the world and because of their large and growing numbers, there is no reason to believe that they can be clubbed as endangered species. They are bred in captivity and can survive on their own because of their intelligence and food habits. Bower (1999), in a report, ‘40-million-year-old fossil teeth and jaw fragments of Bahinia pondaungensis found in Myanmar,’ says that “researchers working in southern Asia discovered a 40-million-year-old fossil teeth and jaw fragments that, in their view, supported the controversial notion that anthropoids originated in Asia.” While this finding in Myanmar by anthropologist Jean-Jacques Jaeger of Universite Montpellier-II in France represents a new species called as the Bahinia pondaungensis, a member of the anthropoid group which includes monkeys, apes, orangutans and humans, what this does help us understand is that this group of great apes survived for millions of years. This also shows that the great apes were not only present in Africa to begin with, but they were present in other parts of the world as well. Because of their near-perfect resemblance to man and the fact their DNA matches that of humans by ninety-eight percent, monkeys and apes are used in tests in research to understand the treatment of “children’s visual disorders,” say King et al., (1988). They are also used in the study of “aqueous humor dynamics and related conditions like glaucoma, the nervous system, and in the study of human behavioral repertoire,” ended King et al., (1988).
In many countries, forest trees are being cut to expand human habitat and also to supply wood to dealers. Logging is a complicated and laborious work and in many counties where logging is done in a big way, “bush meat trade is blatant and widespread,” says John (1997). He goes on to say that in the Republic of Congo (not the former Zaire, but the country to the west of it), researchers found that logging company employees supplemented their income by supplying local hunters with weapons, ammunition, and transport in exchange for a share of bush meat.” This is a bad precedent as bush meat hunting could even outrank habitat loss as a threat to primates becomes imminent. Under such great human population pressure, while it is most unlikely that Chimpanzees will disappear for ever because of poaching, they can definitely become extinct because of the destruction of the ecosystem of which they are living components.
Conclusion
The primates are perhaps the most instinctively surviving mammals on the planet Earth. Humans too belong to the group of primates which include familiar animals like chimpanzees, gorillas, and monkeys, in addition to a few lesser known lemurs like lorises, galagos, pottos, sifakas, indris, aye-ayes, and tarsiers. Two primates from different suborders that were studied here were the Prosimii or the prosimians, and the Anthropoidea, to which humans belong. Lemurs are most found in Madagascar and are protected species, while orangutans, apes, and humans belong to the anthropoidea group and are scattered across the face of Earth. Little research has been conducted using prosimians as they are considered endangered, but a lot of research is done using monkeys, apes and chimpanzees. Most of these tests are conducted on these animals to find solutions to problems that humans face and for finding suitable cures. While these animals are found everywhere and are therefore, used in research, the changing environmental issues could make these animals also face extinction.
Works Cited
Bower, B, (1999), Higher Primates May Have Asian Root, Science News, Journal, Science News, Gale Group, Web, Retrieved December 5, 2013, from http://www.highbeam.com/doc/1G1-57563946.html
King, F, A, Yarbrough, C, J, Anderson, D, C, Gordon, T. P and Gould, K, G, (1988), Science (New York, N.Y.), ISSN 0036-8075, 06/1988, Volume 240, Issue 4858, pp. 1475 - 1482
Lemurs of Madagascar, Exploring Madagascar, a land of cultural and biological richness, WildMadagascar.org, Web, Retrieved December 5, 2013, from http://www.wildmadagascar.org/wildlife/lemurs.html
Stevens, J, R and Mühlhoff, N, (2012), Intertemporal choice in lemurs, Behavioral Processes, Volume 89, Issue 2, Web, Retrieved December 5, 2013, from http://www.sciencedirect.com.ezproxy.apollolibrary.com/science/article/pii/S0376635711001951 p.121–127
Tuxill, J, (1997), Losing Strands in the Web of Life: Vertebrate Declines and the Conservation of Biological Diversity, World Watch, Web, Retrieved December 5, 2013, from http://www.worldwatch.org/system/files/WP141.PDF
